Republicans in the U.S. House of Representatives voted Tuesday night to impeach Homeland Security Secretary Alejandro Mayorkas, claiming he is responsible for a record influx of illegal migrants crossing the U.S.-Mexico border in the past year.

The vote was 214-213 to impeach, but three Republicans sided with the Democrats against it.

Hard-line conservative Republicans have targeted Mayorkas for months but failed by a single vote last week to impeach him when three House Republicans voted against the effort and House party leaders failed to realize that one Democratic lawmaker opposed to the impeachment would show up to vote even though he had been hospitalized awaiting surgery.

The vote Tuesday was close again but came down in favor of impeaching the 64-year-old Cabinet member with the return of Republican Majority Leader Steve Scalise, who missed last week’s vote while being treated for cancer.

Mayorkas became only the second Cabinet member in U.S. history to be impeached, after Secretary of War William Belknap in 1876.

The impeachment of Mayorkas, the political equivalent of an indictment, could prove to be a symbolic victory for his Republican critics, who are looking, as the November elections approach, to attack Democratic President Joe Biden and Democratic lawmakers for the chaos at the U.S. southern border. A record 10,000 migrants a day were apprehended at that border in December.

The Democratic-controlled Senate, with a 51-49 majority, is certain to acquit Mayorkas. A two-thirds vote is needed for a conviction, meaning at least 18 Democrats would have to vote for a conviction if all Republicans did as well.

Now that the House has impeached Mayorkas, the Senate will be compelled to at least open a trial. But it could vote to dismiss the articles, dissolve the trial or refer the articles of impeachment to a committee.

Impeachment of top U.S. officials hinges on whether they have committed “high crimes and misdemeanors.” Mayorkas has said the allegations against him are baseless and he has continued in his job.

Republicans calling for his impeachment say he has violated immigration laws by not detaining enough migrants at the border and by implementing a humanitarian parole program that has allowed people into the country who wouldn’t otherwise qualify to enter. They also allege that he has lied to Congress when he’s claimed that the border is secure.

“The House Committee on Homeland Security’s investigation and subsequent impeachment proceedings demonstrated beyond any doubt that Secretary Mayorkas has willfully and systemically refused to comply with the laws of the United States and breached the public trust,” House Committee on Homeland Security Chairman Mark Green said in a statement after the vote.

The committee’s top Democrat also released a statement after the vote.

“To be clear, this baseless impeachment will do nothing to secure the border – Republicans have admitted as much. It is clear they don’t have a shred of credibility on border security issues. Instead of providing the Department of Homeland Security the resources it needs or working together towards a bipartisan solution, they have rejected any solution for the sole reason that they can have a political wedge issue in an election year,” Representative Bennie G. Thompson said.

Democrats and some legal experts have contended that the debate over whether to impeach Mayorkas is essentially a policy dispute, not a matter that meets the U.S. constitutional standard of whether he has committed “high crimes and misdemeanors.”

Republicans have assailed Biden and Mayorkas for easing border restrictions after Biden defeated Republican President Donald Trump in the 2020 election and changed migration rules Trump had imposed.

Last week, even as many Republican lawmakers pushed for the Mayorkas impeachment, they voiced their opposition to a bipartisan Senate proposal that would have imposed the tightest border controls in years after Trump said he opposed it as not tough enough.

Immigration controls are certain to be a prominent issue in the November presidential contest, where Biden and Trump are likely to again face each other.